Fan



G. F. BAHR July 14, 1942.

FAN

Filed May 17, 1939 4 INVENTOR astalfe j! al ATTORNEYS Patented July 14,1942 FAN Gustave F. Bahr, Bridgeport, Conn., assignor to Casco ProductsCorporation, Bridgeport, Conn., a corporation of Connecticut ApplicationMay 17, 1939, Serial No. 274,111

9 Claims.

The present invention relates to fans, and, more particularly, to themeans for mounting the hub of the fan on the drive shaft.

In prior constructions, the hub of the fan is mounted on the drive shaftby locking means which are adjusted after the hub has been put in place.These locking means have taken the form of bolts threaded into theshaft, lock nuts or set screws which are tightened up after the hub hasbeen put in place` and usually require the hub to be provided withapertures and the like formations through which the operating means oradjusting means for the set screws or other locking means can beinserted and operated.

An object of the present invention is to provide a mounting which willsecurely hold the hub in place on the shaft without requiring furtheroperations to lock it in place. This is accomplished, according to thepresent invention, by providing the hub with a resilient sleeve whichwill receive and grip the drive shaft with suicient friction to causethe hub and the blades carried thereby to be driven by the motor orother means for rotating the shaft.

ln the preferred form of the invention, the hub is hollow and has atubular member projecting from the inner surface thereof so as to extendaxially of the hub. The tubular member can be carried entirely withinthe hollow hub or can project from one end thereof and has an open endthrough which a sleeve of resilient material, such as live rubber, isinserted and secured. The sleeve of resilient material is prol videdwith a bore to receive and grip the end of the drive shaft.

if it is desirable to make the grip on the drive shaft adjustable, thesleeve of resilient material can be compressed, for example, by beingmade so as to project slightly beyond the free end of the tubularmember, and a lock and clamping cap having an aperture to receive thedrive shaft is threaded on the end of the tubular member and intoengagement with the projecting end of the sleeve. i

Upon tightening of the cap, the resilient sleeve will be compressed soas to reduce the bore therein and move the portion of the sleeve to morefirmly grip the surface of the shaft. In mounting the hub on the shaft,the sleeve of live rubber is located within the tubular member and thenut tightened up to lock the sleeve in place. The bore of the sleeve maybe slightly smaller than the shaft, or the sleeve can be compressed sothat it becomes such, and, upon shaft being inserted into the bore, thesleeve will be compressed radially against the tubular member and-applya gripping action to the shaft.

The shaft may be suitably roughened or the sleeve provided with asuitable friction surface or the shaft can be roughened and the sleeveprovided witha suitable friction surface to further aid in the drivingrelation between these elements.

, to force the hub on the end of the shaft and the resilient grippingaction of the sleeve will automatically securely hold the hub in placewithout any further adjustments.

A further feature of this invention resides in the fact that all of theelements of the connector are symmetrically positioned about the axis ofthe hub so that they do not in any way unbalance the hub as would be thecase if set screws or the like were used.

Also, if in manufacturing the hub it should be' slightly out of balance,the resiliency of the sleeve will permit the hub to assume a truebalance on the shaft when the latter is rotated.

Other features and advantagesof the invention will be apparent from thespecification when considered in connection with the drawing, in which:

Figure l is a longitudinal sectional view of the hub.

of Fig. i.

Fig. 3 is an exploded view of the tubular member sleeve and 4lockingmember.

Fig. 4 is a fragmentary longitudinal sectional `view of the hub, showingthe relation of the connecting means when vthe sleeve is undercompression and before the drive shaft is inserted.

Fig. 5 shows an electric fan, with part of the hub broken away, showingthe connection of the 40 present invention.

In the illustrated form of the invention, a driving motor l0 has a driveshaft il projecting therefrom and on which the hub i2 having a pluralityof radially projecting fan blades i3 is t'mounted. Upon rotation of themotor, the fan blades will be driven and cause a stream of air to becreated.

The present invention provides a novel means wherein the hub can besecured to the drive shaft 5o for rotation therewith without requiringany operations or adjustments to be made after the hub is in place. Inthe illustrated form of the invention, the hub l2 comprises a hollowshell i4 having a tubular member l5 within the hub prothe 5| jectingaxially thereof. This tubular member With this construction, it ismerely necessary Fig. 2 is a sectional view, taken along line 2 2preferably lies within the trailing edge of the hub. This edge of thehub is provided with a flange Ma overlapping the front of the motor, asshown in Fig. 5, so that the member is completely enclosed by the hub.

If desired, the member can be formed integrally with the hub, or it canbe formed as a sleeve I6 having a portion Ilia overlapping and securedto an annular member Il projecting inwardly from the nose of the hub.

Disposed within the tubular member is a sleeve I8 of resilient materialhaving a bore to receive the end of the drive shaft and form the driveconnection therewith. The sleeve is illustrated as having a reduced neckI8a which extends into the member II. In the present preferred form ofthe invention, the sleeve I8 is made up of live rubber, though the samemay be made of any resilient material which can be compressedsuiiiciently to apply a gripping force to the end of the drive shaft.

In order to increase the grip of the sleeve I8 on the shaft or to adaptit to receive shafts of slightly smaller diameter, the present inventionforms the resilient sleeve so that it extends slightly beyond the freeend of the tubular member and is placed under compression by means of acap I9 threaded on the free end of the tubular member and engaging theend of the sleeve to place it in a state of compression as shown in Fig.4. By properly adjusting the cap, it will be understood that variousdegrees of compression can be had in the sleeve, and, consequently,various amounts of gripping action will take place between the frictionsleeve and the drive shaft.

It will be further appreciated that by compressing the sleeve andreducing the bore therein, proper driving connection can be had withdrive shafts having slightly smaller diameters.

If desired, the engaging surfaces of the resilient sleeve or drive shaftor both can be provided with friction surfaces to resist rotationbetween these elements.

When a fan hub is to be assembled, the blades are inserted in the slots20 so that they project radially therefrom. The resilient sleeve I8 islocated in the tubular member I 6 and the cap I9 is then threaded on theend of the member to lock the sleeve in position and place it undercompression, the amount of compression depending upon the size of theshaft to be inserted therein and the pressure of the grip necessarythereon to prevent relative rotation between the hub and shaft.

As will be seen, all of the elements of the assembled coupling meanswill be symmetrically disposed about the axis of the hub which coincideswith the axis of rotation of the fan so that objectionable `vibrations,due to an unbalanced condition which might be present when set screws orthel like are used as securing means, will not occur.

Further, should any slight unbalance be present in the hub as a resultof the manufacturing operation, the resiliency of the sleeve will permitthe hub to properly center itself on the shaft in balanced conditionupon rotation of the shaft.

When a hub has thus been completed, it is assembled with the motor byinserting the motor shaft into the resilient sleeve and forcing ittherein, as shown in Fig. 1. This will cause the resilient sleeve to beforced against the inner surfaces of the tubular member and becompressed, the resiliency of the sleeve will then cause the sleeve togrip the end of the shaft with sufficient pressure to hold the hub andthe blades carried thereby in driving relation with the drive shaft. Nofurther adjustments or manipulations are required, the assemblingoperation being complete upon the insertion of the shaft into theresilient sleeve. y

Thus, the present invention eliminates the necessity of tightening setscrews or other locking means after the hub has been placed on theshaft.

This is an important feature, when, as in the present type of fan, thesecuring means is entirely within the shell, forming the hub which isprovided with a flange Illa that overlaps the end of the motor casing,as shown in Fig. 5, making it extremely difficult to provide any meansfor locking the hub in place after it has been located on the driveshaft.

Variations and modifications may be made within the scope of thisinvention and portions of the improvements may be used without others.

I claim:

1. In a fan having a propeller mounted on the end of a shaft whichconstitutes the sole support for said propeller, means for removablymounting the hub of the propeller solely by friction on the end of' thedrive shaft, comprising a rigid tubular member secured to said hub andcoaxial therewith; a sleeve of resilient material disposed within saidtubular member and adapted to receive the end of said drive shafttelescopically within its bore; fixed support means carried at one endof said tubular member and abutting one end of said resilient sleeve;and movable clamping means carried by the opposite end of said tubularmember adapted to engage the other end of said resilient sleeve forcompressing it axially within said tubular member, said axialcompression bringing said sleeve into radial gripping relation with thedrive shaft, said resilient sleeve constituting the sole drivingconnection between said shaft and said propeller.

2. In a fan having a propeller mounted .on the end of a shaft whichconstitutes the sole support for said propeller, means for removablymounting the hub of the propeller solely by friction on the end of thedrive shaft, comprisng a rigid tubular member secured to said hub andcoaxial therewith; a sleeve of resilient material disposed within saidtubular member and adapted to receive the end. of said drive shafttelescopically within its bore; fixed support means carried at the frontend of said tubular member and abutting the front end of said resilientsleeve; and means threaded to the rear end of said tubular memberadapted to engage the rear end of said resilient sleeve for compressingit axially within said tubular member, said axial compression bringingsaid sleeve into radial gripping relation with the drive shaft and saidresilient sleeve constituting the sole driving connection between saidshaft and said propeller.

3. In a fan having a propeller mounted on the end of a shaft whichconstitutes the front support for said propeller, means for removablymounting the hub of the propeller solely by friction on the end of thedrive shaft comprising a rigid tubular extension projecting coaxiallyfrom the rear surface of the hub, the latter'extending over and closingthe forward end of said extension; a sleeve of resilient materialdisposed within said tubular extension adapted to receive the end ofsaid drive shaft te1esc0pica11y within its bore, and having one endabutting the hub at the forward end of said tubular extension; andmovable clamping means Acarried by the rear end of said tubularextension adapted to engage the rear end of said resilient,4 sleeve foraxial compression thereof to bring the sleeve into gripping relationwith the drive shaft, said resilientl sleeve constituting the soledriving connection between said shaft and said propeller.

4. In a fan having a prop-eller mounted on the end of a shaft whichconstitutes the sole support for said propeller, means for removablymounting the hub of the propeller solely by friction on the end of thedrive shaft, comprising a rigid tubular extension projecting coaxiallyfrom the rear surface of the hub, the latter extending over and closingthe forward end of'said extension; a sleeve of resilient materialdisposed within said tubular extension adapted to receive the end ofsaid drive shaft telescopically within its bore, and having one endabutting the hub at the forward end of said tubular extension, the rearend of said resilient sleeve normally projecting slightly beyond therear end of said tubular extension; and movable clamping means carriedby the said tubular extension at its rear end for engaging the normallyprojecting end of said resilient sleeve and compressing it axially intosaid tubular extension for bringingv said sleeve into radial grippingrelation with said shaft, said resilient sleeve constituting `"the soledriving connection between said shaft and said propeller.

5. In a fan having a propeller mounted on the end of a shaft whichconstitutes the sole support for said propeller, means for removablymounting thevhub of the propeller solely by friction on the end of thedrive shaft, comprising a rigid tubular extension projecting cqaxiallyfrom the rear surface of the hub, the latter extending over and closingthe forward end of said extension; a sleeve of live rubber disposedwithin said tubular extension adapted 'to receive the end of said driveshaft telescopically within its bore and having one end abutting the hubat the forward end of the tubular extension, the rear end of said liverubber sleeve normally projecting slightly beyond the rear end of saidtubular extension; and a cap threaded to the rear end of the saidextension, said cap having an annular.

flange for engaging the projecting end of said resilient sleeve andadapted to compress it axially upon threading the cap over the tubularextension, said axial compression bringing the rubber sleeve intolateral gripping relation with said driving shaft, the rubber sleeveconstituting the sole driving connection between said propeller and saidshaft.

6. In a fan propeller having a hollowcupshaped hub of rigid materialwith a plurality of blades projecting radially therefrom, means forremovably mounting said propeller solely by friction on the end of adrive shaft, comprising a rigid tubular member projecting coaxially fromthe inner surface of said hub and completely within the hollow of thelatterl said memyber being closed at the end forming a junction with thehub; a sleeve of live rubber adapted to eral gripping relation with saiddrive shaft, said sleeve constituting the sole driving connectionbetween said propeller and shaft.

'7. In a fan propeller having a hollow cup'- shaped hub of rigidmaterial with a plurality of blades projecting radially therefrom, meansfor, removably mounting said propeller solely by friction on the end ofa drive shaft, comprising a rigid tubular member projecting coaxiallyfrom the inner surface of said hub and completely within the hollow ofthe latter, Said member being closed at the end forming a junction withthe hub; a sleeve of live rubber adapted to receive the end of saiddrive shaft telescopically within its bore disposed: within said tubularmember and abutting. the closed end thereof;

and means threaded over the end of said tubular member and movable intoengagement with the end of said rubber sleeve for axial compressionthereof, whereby said sleeve is brought into lateral gripping relationwith said drive shaft, said rubber sleeve constituting the sole drivingcon- -nection between said propeller and said shaft.

8. In a fan propeller having a hollow cupshaped hub of rigid materialwith a plurality of blades projecting radially therefrom, means forremovably mounting said propeller solely by friction o'n the end of adrive shaft, comprising a rigid tubular member projecting coaxially fromthe inner surface of said hub and completely within the hollow of thelatter, said member being closed at the end forming a junction withreceive the end of said drive shaft telescopically within its boredisposed within said tubular member and abutting the .closed endthereof;

and movable clamping means carried by the open end of said tubularmember yfor engaging the end of said live rubber sleeve to compress itaxially, whereby said sleeve is broughtinto latthe hub; a sleeve of liverubber adapted to receive the end of said drive shaft telescopicallywithin its bore disposed within said tubular member and abutting theclosed end thereof, the

rear end of said sleeve extending slightly beyond,

the opposite end of said tubular member; and a cap threaded to the rearend of said tubular member, said cap having an annular flange forengaging the projecting end of said rubber sleeve to compress it axiallyinto said tubular member, axial compression of the sleeve bringing itinto lateral gripping relation with said drive shaft,

said rubber sleeve constituting the sole driving connection between saidshaft and said propeller.

9. A fan comprising a propeller having a hollow cup-shaped hub of rigidmaterial and a plurality of blades projecting Dradially therefrom; amotor having a casing and a drive shaft projecting therefrom; means forremovably mounting said fan propeller on the end of said drive shaftwith the edges of said hub extending substantially to the casing of themotor to form an apparently continuous surface, said means comprising arigid tubular member projecting coaxially from the inner surface of saidhub and completely within the hollow thereof, said member being closedat its forward end which fome its junction with the hub; a sleeve oflive rubber adapted to receive the endof said drive shaft telescopicallywithin its bore disposed within said tubular member and abutting theclosed end thereof; and movable clamping means carried by the rear endof said tubular member for engaging the end of said live rubber sleeveto compress the latter axially, whereby said sleeve is brought intolateral gripping relation with said drive shaft, said rubberconstituting the sole driving connection between said shaft and saidpropeller.

GUSTAVE F. BAHR.

